Here is the article that I used to build my own injection system that used vacuum port of carb. Note that the drawing shows the reed valve in line with the vacuum advance~! This is a mistake, because if you do this and turn the reed valve off, then you have no vacuum advance~!. So, all I did is run a single line to a port at the base of the carb. It works~! http://www.motherearthnews.com/Do-It...on-System.aspx